What is Prime Cost? The One Number That Decides if Your Restaurant is Profitable

This post is a working operator’s guide to prime cost. What it is, how to calculate it, what good looks like, and how to use it as the steering wheel of your business instead of a number you check once a month after the books close.

What prime cost actually is

Prime cost is the sum of your cost of goods sold (COGS) and your total labor cost, expressed as a percentage of total sales. In other words, what percentage of your revenue goes to the cost of goods and labor.

The formula:

Prime Cost = (COGS + Total Labor) / Total Sales

COGS includes food, beverage, and any consumable goods directly tied to producing what you sell. Total labor includes wages, payroll taxes, benefits, and any other employment-related costs for everyone on the payroll.

The reason these two numbers get combined is that they’re the two largest controllable expenses in any restaurant. Rent is fixed. Utilities mostly are. Insurance, licenses, and fixed overhead don’t move much month to month, and don’t provide many levers to save cost. But food cost and labor cost move every day, and together they typically represent around 60% of total sales. If you track just one KPI closely, make it Prime Cost.

A simple example. A restaurant does $100,000 in sales for the month. COGS came in at $30,000. Total labor was $32,000. Prime cost is $62,000, or 62% of sales. That leaves $38,000 to cover everything else: rent, utilities, marketing, insurance, equipment, and profit.

What a healthy prime cost looks like

Industry consensus is that full-service independent restaurants should target prime cost at 60% of sales or below. Quick service can run lower, sometimes in the mid-50s. Fine dining tends to run higher, sometimes into the mid-60s, because labor costs scale up with service level.

Some overall context on the benchmarks:

- Below 55%: Exceptional. Either very efficient operations or strong pricing power. Usually indicates a tight, well-run business.

- 55% to 60%: Healthy. Profitable operations consistently land here.

- 60% to 65%: Watch zone. Still viable but the cushion is thin. Most cost increases will push you into the red, leaving little to no margin for error. Need a repair? Need a recruiter? You’re in the red that month.

- 65% to 70%: Trouble. Either revenue isn’t where it needs to be or one or both cost categories are out of line. You are not profitable or won’t be for long.

- Above 70%: Crisis. You’re losing money, and there are numerous major leaks that aren’t being addressed. 

Again, those benchmarks vary by concept and market, but they hold roughly true across the industry. A QSR is entering crisis mode closer to 65%, and a fine-dining restaurant is reaching exceptional under 60%. This is because a scratch kitchen with high-end ingredients and skilled labor will run higher than a fast-casual concept with simplified prep. The right target for your operation is the one that leaves enough margin to cover everything else and produce profit.

Why prime cost is the catch-all metric

Food cost and labor cost are each useful numbers on their own. But each one tells you about a single category. Prime cost is the metric that captures the full operational story.

Think of it this way. Your food cost percentage tells you how well you're managing your kitchen, your purchasing, your portions, and your menu mix. Your labor cost percentage tells you how well you're managing your schedule, your staffing levels, and your wage structure. Both are real and both are important. But neither one, by itself, tells you whether the business is working.

Prime cost does. It's the single number that captures every controllable decision you make about how the restaurant produces what it sells. Pricing, purchasing, recipes, portions, waste, scheduling, training, productivity, hiring, retention. All of it eventually flows into one of those two cost categories, and the combined number is the final scorecard.

That's what makes it powerful. When prime cost is on target, you don't have to dig into the components to know the operation is in control. When it's off, you have one place to look first, and then you drop down into food cost and labor cost separately to find the source. The prime cost number is the alarm. The component numbers are the diagnosis.

It's also the metric that catches problems the components alone hide. A restaurant can have a perfect food cost percentage and a labor cost percentage that looks fine, and still have a prime cost that's too high because both are sitting at the upper end of their healthy ranges at the same time. Each component looks acceptable in isolation. Together they're choking the operation, and Prime cost surfaces that immediately. Looking at the components separately wouldn't.

This is why operators who run their margins well treat prime cost as their North Star number. The components matter for diagnosis. The combined metric matters for control.

How to actually use prime cost

Most operators calculate prime cost monthly, at the end of the month, when the books close. That’s too late to do anything about it. The month is over. The labor decisions have been made. The food has been ordered, prepared, and sold. You’re looking at a report card, not actionable data.

The operators who actually run their margins well track prime cost weekly, and watch trends. Our SHS Operating System does this for you. If doing it manually, every Monday, pull the numbers for the previous week:

- Total sales

- Food and beverage purchases (adjusted for inventory if possible, otherwise use purchases as a proxy)

- Total labor cost including payroll taxes

Add the two cost categories. Divide by sales. Look at the number against your target.

If you’re at target or below, the operation is running well. Look for what’s working and reinforce it.

If you’re over target, you have one week of data, not one month. You can adjust this week’s schedule, this week’s ordering, this week’s pricing decisions. The damage from last week is done. The damage from this week is preventable.

This shift, from monthly hindsight to weekly control, is the single most valuable thing an operator can do with the metric. The math doesn’t change, but the cadence does, allowing you to actually make use of it. 

What pushes prime cost out of line

When prime cost drifts, the cause is one of these:

Food cost drift:

- Vendor price increases without corresponding menu repricing

- Portion creep (cooks plating heavier than the recipe calls for over time)

- Increased waste from prep inefficiency, mistakes, or quality issues

- Menu mix shifting toward lower-margin items

- Comp and void abuse, theft

Labor cost drift:

- Schedule built without a sales forecast, leading to inefficiency (overstaffing on slow shifts)

- Overtime running without controls

- Wages drifting up through raises without corresponding 3x margin adjustment

- Poor training systems or managerial oversight, resulting in schedules that are heavier than required for your operation 

- New hires being onboarded without a clear ramp plan (paying full wage for partial productivity)- 

Most of these are slow drifts, not sudden spikes. Operators rarely wake up one morning to a 5-point prime cost jump. They wake up to a 5-point jump that’s actually 12 months of 0.4-point drifts that nobody flagged.

This is why weekly tracking matters. A drift of half a point in one direction is easy to dismiss. The same drift sustained over 20 weeks is what makes the difference between a profitable year and a stressful one.

Calculating prime cost correctly

A few common mistakes that distort the number:

Using purchases instead of true COGS. Purchases tell you what you bought, not what you used. True COGS accounts for inventory:

COGS = Beginning Inventory + Purchases - Ending Inventory

If you’re not doing weekly or monthly inventory, using purchases is a reasonable proxy, but it will not be fully accurate. A heavy purchasing week inflates your COGS even though the food is sitting on the shelf, not on plates.

Excluding payroll taxes and benefits from labor. Wages alone don’t capture true labor cost. Add payroll taxes (typically 7.65% federal, plus state unemployment), workers’ comp insurance, any benefits, and any service-charge or tip-pool administration costs. The difference between gross wages and fully loaded labor cost is usually 15 to 25%.

Counting revenue inconsistently. Total sales for prime cost purposes should be net of discounts, comps, and voids. Gross sales overstate your denominator and make prime cost look better than it is.

Where to start this week

If you don’t currently track prime cost, here’s the starting sequence:

1. Pull your last full week of sales (net of comps, voids, and discounts).

1. Pull all food and beverage purchases for that week.

1. Pull your full labor cost for the week, including taxes and benefits if you can.

1. Add COGS and labor. Divide by sales. 

1. Compare to the 60% target.

That’s your starting baseline. The first time you do this, the number will tell you where you actually stand. From there, the work is repeating the calculation every Monday, watching the trend, and acting on the drifts before they compound.

The operators who run their restaurants well aren’t tracking dozens of metrics with a microscope. They’re tracking the right few, weekly, and acting on what they see. Prime cost is the most important of those few. If you only have time for one number, this is the one.

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The SHS Operating System is built around real-time prime cost tracking, automatically pulling your sales, COGS, and labor numbers into a single executive dashboard and live P%L. Five minutes of data entry a day and your prime cost picture stays current. [See the SHS OS →]